|
|
03-03-2013, 01:25 PM | #199 | |
Brigadier General
126
Rep 4,145
Posts |
Quote:
Cheers.
__________________
2017 F80 YMB.
|
|
Appreciate
0
|
03-03-2013, 01:36 PM | #200 |
-
11817
Rep 23,187
Posts |
mine has never leaked. early build 08s dont have hole in the cap so never has happened to me?
__________________
02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW exhaust|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|apr gt 250 & splitter|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs| |
Appreciate
0
|
03-03-2013, 03:47 PM | #201 |
Brigadier General
97
Rep 3,246
Posts |
Mine doesn't leak either, but have taken the preventative measure of putting a wristband on the PS reservoir, but have never felt that it was wet...many track days, many different tracks... :
__________________
mods: track ready stuff
|
Appreciate
0
|
03-05-2013, 12:38 AM | #202 | ||||||
Grease Monkey
293
Rep 2,646
Posts
Drives: 2011 E90 M3,1994 Euro E36 M3/4
Join Date: Apr 2006
Location: Fort McMurray, Alberta, Canada
|
Sorry it took so long to reply, here are my answers/rebuttals.
Quote:
Yes this is correct, no substantial increase in peak torque is gained by a long stroke engine versus a short stroke engine. Quote:
Lets compare two engines with the same displacement, one undersquare, one oversquare. The undersquare engine has less room for in the combustion chamber for intake/exhaust valves so as a result their diameter and is smaller. Smaller intake vaves/ports/runners end up having higher velocity flow at lower RPM compared to larger ones, couple this with the higher piston velocity that is a trait of longer stroke engines and you have an engine that achieves peak VE at a low RPM. Since peak torque occurs at peak VE that puts peak torque at a low RPM. In an oversquare engine the combustion chamber is large enough to house larger valves/ports/runners. These larger valves/ports/runners allow for the engine to breath at higher RPMs and make more peak power. Since an oversquare engine has lower piston velocity than an undersquare engine of the same displacement turning at the same RPM, the engine needs some RPM to achieve peak VE and peak torque. The plus to this is the fact that the oversquare engine is able to rev higher as a result of the reduced piston speeds and inertia. This mechanical ability of the rotating assembly to rev higher coupled with the better flow characteristics of the ports/valves/runners will make for an engine that can spin much faster and maintain torque at RPMs much higher than an undersquare engine. Quote:
Yes, you were right on this one, I was a little bit off on what I was trying to convey. Piston acceleration/deceleration and dwell off of TDC/BDC is determined by the rod to stroke ratio. Overall piston velocity is a function of stroke length. Since all otto-cycle engines have 720 degrees to complete a cycle (four complete strokes of the piston; Intake, compression, power, exhaust) if two engines have the same displacement but one has a stroke that is 30% longer, it will have a 30% higher peak piston velocity at the same engine speed (RPM) Quote:
I can't say that you're wrong on this, but the more flat the torque curve, the more linear the power delivery! I am sure the engine you describe would be a great engine too. Quote:
It is not limitations in actual airflow that I was referring to but rather limitations in port design, runner length, airbox volume and exhaust header design. The S65 has amazing breathing capabilities as shown by it's ability to maintain torque at a high RPM. To get this airflow required to make the engine breath at the high RPMs that it is capable of, large, free flowing ports, runners, throttle bodies and intake trumpets were required. The negative to these free flowing parts is the fact that large ports, runners, throttle bodies and intake trumpets do not lend themselves to good port velocities and cylinder filling at low RPM. The solution to this was to use the VANOS to independently adjust intake and exhaust camshaft timing, duration and valve overlap to allow the engine to take advantage of the resonance tuning effect over the entire power band. Although variable camshaft timing is not new, the VANOS system in the S65 had more adjustability at a faster rate than most of the other manufacturers were using at the time it was released. The key element to making this system work was that the MSS60 ECM which had the computing capacity to handle 200 000 000 calculations per second which at the time of release of the engine was the smartest ECM in a production vehicle. This ECM allowed the VANOS system to be able to be controlled at the speed and accuracy that was required for it to be effective in allowing the cam timing to always be at the optimum position for max power I know that I am rambling a bit on this section, but I have to be adamant around the fact that the reasoning for the S65 not making more torque than it does is absolutely a result of the limitations caused by packaging. Given more space the engine could have made more torque (the bump in the hood wasn't for styling, it was put there to allow the intake plenum to fit). I am sure the final design that we got was a result of the best compromise they figured they could reach with the available space, styling constraints, cost and performance. Quote:
__________________
Last edited by BMRLVR; 03-05-2013 at 12:51 AM.. |
||||||
Appreciate
0
|
03-05-2013, 12:59 AM | #203 |
Holding Out
8
Rep 246
Posts |
Weight.
__________________
E92 AW/FR Ext 6MT/ZCP/ZPP/ZTP
"The M3 M DCT simply does everything well except tow a hot-dog stand. It may even be the second-best car in the world after the M3 manual. " |
Appreciate
0
|
03-05-2013, 03:13 AM | #204 |
BMX Godfather
12
Rep 137
Posts |
Had my car for 3 days and so far cannot find a single downfall other than my paranoia! To scared to leave or drive my car anywhere...haha...
|
Appreciate
0
|
03-05-2013, 04:03 AM | #205 |
Private First Class
18
Rep 185
Posts
Drives: BMW
Join Date: Oct 2011
Location: Taiwan
|
That every generation of the M3 gets faster and you want to buy another one. It might end this time for me with the end of high revving N/A motor.
Torque of the M3 isn't really an issue for me. For lazy people that wants to stay in 6th or 7th to pass on a highway then that's a different story. I usually just down shift if I need more speed. I think when people say the M3 lacks torque is because of the flat torque curve BMW engines put out. I do feel the E90's weight compare to the E46. But still own both so I should stop comparing LOL.
__________________
[E30 325i | E39 528i | E46 M3 | E70 X5 | E90 M3 | F25 X3 | NA1.5 NSX | 718 GT4]
Last edited by Envyscorpio; 03-05-2013 at 07:08 AM.. |
Appreciate
0
|
03-05-2013, 08:24 AM | #206 |
First Lieutenant
4
Rep 350
Posts |
Power steering leak. I believe it leakes cause the fluid gets hot when your driving hard. When it gets hot it expands so it over flows. The fluid cooler is directly behind the bumper suport. Remove it from the tabs, hang it lower so it is exposed. It might look getto but mine dont leak anymore. That or keep an eye on your fluid level. Suck some out so it doesnt over flow when drivinh hard. Just make sure to add when your done.
Do a search, Theres a thread about it here. |
Appreciate
0
|
03-05-2013, 09:41 AM | #207 |
Major
2037
Rep 1,198
Posts |
Shifter.
__________________
11’ E92 ///M3
15’ F82 ///M4 18’ G30 540i ///Msport 21’ G20 ///M340i 24' i20 iX xDrive50 Last edited by Cortexiphan; 03-05-2013 at 01:23 PM.. |
Appreciate
0
|
03-05-2013, 10:04 AM | #208 |
-
11817
Rep 23,187
Posts |
__________________
02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW exhaust|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|apr gt 250 & splitter|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs| |
Appreciate
0
|
03-05-2013, 09:10 PM | #209 |
Registered
0
Rep 3
Posts |
Weight and need for an even stiffer suspension setting.
__________________
You know you're a redneck when you can fit three cars in a two-car garage! '08 e90 M3 DCT, '98 e36 M3 Sedan, '95 Porsche 993 (track) |
Appreciate
0
|
03-05-2013, 09:27 PM | #210 |
Second Lieutenant
21
Rep 294
Posts |
Weakness=are probably the brakes and its amazing amount of dusting it does
Weakness#2 The auto start/stop mechanism is stupid, because the battery gets too low too quickly and shuts everything off. Weakness #3. Its really not a weakness but always aware of when I park the car. I sometimes get a fealing that someone is going to key it just because its a nice car. Nothing else comes to mind, its great vehicle and a great engine!!
__________________
2015 M4
Looking for a 50' SeaRay |
Appreciate
0
|
03-06-2013, 01:37 AM | #215 |
Lieutenant Colonel
79
Rep 1,618
Posts |
Torque, fuel consumption, weight, brakes, stock exhaust.
__________________
Performance Seats, Exhaust, Splitters, Pedals, Steering Wheel / RB Turbos / M3 CF Roof / Brembo GT BBK 355/345 / Rollcage / Forge FMIC / Quaife LSD / Öhlins Road & Track / M3 Suspension Parts / Solid Subframe Bushings / Vorshlag Camberplates / Megan Racing Toe Links / LeatherZ Gauges / Extended M3 DCT Paddles / ER Sports OC / AR OC / Aux Radiator / AR DPs / Alpina TCU / COBB Pro-Tune
|
Appreciate
0
|
03-06-2013, 09:52 AM | #217 |
-
11817
Rep 23,187
Posts |
haha honestly never even thought about our car having one. never used it in over 4 years.
__________________
02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW exhaust|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|apr gt 250 & splitter|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs| |
Appreciate
0
|
03-06-2013, 10:03 AM | #218 | ||||||
Colonel
99
Rep 2,000
Posts |
Quote:
Quote:
Quote:
OK, reducing the rod length/stroke ratio is a mixed blessing. First (and as you've said), you pull the piston off top dead center more quickly, giving a stronger early signal to the intake, thus leading to better cylinder filling at low rpm. In addition, you mechanically take better advantage of the short-lived cylinder pressure spike, because due to increased rod angularity, you reach max energy conversion into torque by enabling a 90 degree angle between the rod and a line drawn from the crank throw to the crank centerline earlier in the powerstroke. Presto! More torque. As revs rise, however, and the engine moves toward max VE (and above), rod angularity starts to hurt you, because you are generating more friction due to increased side loads on the piston. In addition, those low-rpm benefits erode, because you begin to take advantage of the intake and exhaust resonances along with more optimum cam timing. At high rpm, "short" rods (in relation to stroke) just hurt you powerwise, eating up those low-rpm torque babies, and more. Quote:
Quote:
Have you checked out the exhaust headers on the S65? They are not only works of art, but IMO they are the primary reason why the torque peak is at an artificially low 3900 rpm on this engine. Those long runners are optimum for low-rpm exhaust tuning, while the rest of the engine seems to be designed for high-rpm greatness. If they tuned those runners for a higher-rpm resonance, you'd need even less underhood space, while gaining torque because the exhaust tuning benefits occur at a more "natural" rpm, dictated by the rest of the design. Quote:
Be honest, now. Are you insisting that raising the torque by 11% on this engine while keeping the same peak power at 8300 would somehow make for a less capable and exciting offering? Bruce Last edited by bruce.augenstein@comcast.; 03-06-2013 at 10:08 AM.. |
||||||
Appreciate
0
|
03-06-2013, 10:32 AM | #220 |
Second Lieutenant
11
Rep 207
Posts |
I'm gonna go out on a limb here and speak for the lack of torque crew in this thread and say that the lack of torque we are refering to is NOT in reference to passing a mini van on the highway.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|